# 成员运算符  in  /  not in
a = '123'
b = '12'
print(b in a)      # True

a = '123'
b = '12'
print(b not in a)  # False

# 身份运算符 is  /  is not
a = '123'
b = '123'
print(b is a)      # True

a = '123'
b = '123'
print(b is not a)  # False

a = [1, 2, 3]
b = a[:]
print(a)       # [1, 2, 3]
print(b)       # [1, 2, 3]
print(b is a)  # False
print(b == a)  # True
